Does cell phone radiation affect human health?

San Francisco city is debating whether to require cell phone sellers to put a label about the amount of radiation levels emitted by cell phones on the cell phone. State of Maine also has a similar bill in work. Increasing amount of people in the world have at least one cell phone, increasing percentage of cell phones are smart phones (with more wireless signals, mobile network, wi-fi, bluetooth, and gps signal), and cell phones use the same radiation as microwave uses. It becomes a hot issue whether cell phone radiation affect people's health, particularly brain health.

Check wikipedia article Mobile phone radiation and health,
you can see that a lot of research has been done. From these research works, however, no convincing evidence proves one way or the other. Some research concludes that cell phone radiation is harmful to human health, some research think the cell phone signal is too weak to be harmful, and other research concludes that phone radiation is beneficial to the health.

If you have concerns about the potential danger of cell phone radiation, you may consider methods to disable some wireless signals, or use headset during the phone conversation.

BTW, although it is questionable whether cell phone radiation affect your health, it is very clear that overusing cell phone (like texting and calling during driving or walking) is a danger to public safety.

Wireless Signal Series: What is Airplane mode on Android phone

Airplane mode on Android phone is very useful to me (airplane mode also exists for other types of smart phones). You can go Menu -> Settings -> Wireless & Networks (for Android 2.1, Wireless controls for Android 1.6) -> Airplane mode to check/enable or uncheck/disable Airplane mode.

If you check Airplane mode, you will disable all wireless signals including mobile network signal (voice and data), wireless signal, and bluetooth (GPS signal still works). So you can not make or receive a phone call, or use 3G signal to surf Internet. Why is airplane mode useful? Intuitively, you need to check airplane mode when you are on a flight. But it is more than that. Some people put their Android phone in the bedroom at night. They need to check airplane mode before going to bed. Otherwise, they may be awaken by the phone call or incoming email notification. Airplane mode is also useful when you bring your phone to a meeting room, movie theater (Silence is Golden), church service, etc.

There is a difference about airplane mode for Android 2.1 (Nexus One uses Android 2.1) and Android 1.6 (G1 Dream uses Android 1.6). For Android 2.1, after you check airplane mode, you can still enable Wi-Fi (Menu -> Setting -> Wireless & Networks -> Wi-Fi) to surf Internet (but you can not enable bluetooth); for Android 1.6, after you check airplane mode, you can not enable Wi-Fi (can not enable bluetooth either). I do not know the change is according to the design or by accident.

Wireless Signal Series: What are wireless signals on Android phone

Smart phones like Android phone usually receive three or four wireless signals. People is easily confused about these signals and puzzled about how to disable these wireless signals.

Here is some description about what wireless signals are on Android phone and other smart phones.

1) Mobile network. This is the signal from mobile carriers like Verizon, AT&T, T-mobile, and Sprint. You need to pay these carriers to use this signal. Based on mobile network signal, there are voice service (phone call), text message service, and data service. For the data service, there is 2G and 3G network signal. For Android phone, you can set them from Menu -> Wireless & Network -> Mobile networks.

2) Wi-Fi. This is the signal from your home wireless router, your company wireless data network, wireless network in public libraries, hot spot in cafe shops, bookstores, car service waiting rooms, airports, etc. You can use Wi-Fi to access Internet. More and more places offer Wi-Fi signals, free or not. For example, in November 2009, Google announced that it offers free Wi-Fi in 47 airports and on Virgin America airplanes. For Android phone, you can view what Wi-Fi signals are available from Menu -> Wireless & Network -> Wi-Fi settings.

3) Bluetooth. This is a short distance wireless signal. You can use it to connect with laptop or car with bluetooth functionality to transfer data. Or you can use bluetooth headphone to make phone call when you drive (strongly discouraged!). For Android phone, you can view bluetooth setting from Menu -> Wireless & Network -> Bluetooth settings.

4) GPS. This is a wireless signal sent from satellites about your phone location (latitude and longitude) about the phone. It's free. But sometimes it may be battery power consuming.

How can we disable all these wireless signals or individual wireless signals on Android phone?

1) To disable all signals (except GPS signal), use airplane mode. Menu -> Wireless & Network, check Airplane Mode. It disables phone and data service provided by mobile carrier, Wi-Fi, and bluetooth. But it does not disable GPS signal. You want to need this because you are required to do so on the flight, you are sitting in a meeting room, or you put your phone besides the bed, but do not want someone to interrupt your sleep by phone call or incoming email notification. Read this article for more information about airplane mode and airplane mode difference between Nexus One ((Android 2.1)) and G1 Dream (Android 1.6).

2) To disable GPS signal, go Menu -> Location & Security settings, and then uncheck Use GPS satellites. You want to do this because you want to save battery life.

3) To disable bluetooth signal individually, go Menu -> Wireless & Network, and then uncheck bluetooth. You want to do this because 1) you never use the bluetooth signal, like me, or 2) you are concerned about the bluetooth radiation.

4) To disable Wi-Fi signal individually, Menu -> Wireless & Network, and then uncheck Wi-Fi. You want to do this sometimes because you want to save battery life.

5) To disable data service provided by carrier, you can install an app called APNDroid (APN stands for Access Point Names) to do this. You do this when you want to use Wi-Fi rather than 2G/3G signal provided by mobile carrier to surf Internent. Why do you want to do this? a) In some phone service packages, data service is charged according to your usage. So when Wi-Fi signal is available, people want to use Wi-Fi signal to surf Internet for free instead of pay usage fee to mobile carreirs. b) In many cases (not always), Wi-Fi data transfer speed is higher than 3G mobile network.

Update on January 19, 2009: add a link about airplane mode.

AT&T poor signal in bay area

Verizon is believed by most people to have the best quality of wireless signal. I and all of my friends thinks so. AT&T had the largest wireless user base for a period of time. AT&T sometimes also claims that it has the best quality of wireless signal, none of my friends (in New York, Boston, Seattle, Illinois, Dallas, Houston, San Francisco, Los Angeles. etc) believe this.

Because of the flood of iphone users, AT&T wireless network is overwhelmed since 2007, especially in New York and San Fransisco. There are many dropped calls. AT&T even urges iphone users to use less data.

But the poor quality of AT&T is not a new problem because of iphone, at least in the bay area. Even T-mobile has a much better signal than AT&T in the bay area, although T-mobile signal bothered me a lot when I lived in Winchester county, NY and Seattle. T-mobile has a very good signal at my office, my wife's office, and my home while AT&T has a poor signal in all of these places.

For people who do not use phone a lot in bay area, I recommend T-mobile prepaid phone. Using 35% Bing Cashback, you can talk 1000 anytime minutes by spending only $65. It is much more flexible and cost-effective than to sign a two-year contract.